Field of the Invention
The present disclosure relates to an ink discharging apparatus and an ink discharging method.
Description of the Related Art
Radical polymerizable inks and cation polymerizable inks are used in active energy ray curing inkjet recording methods. Among these inks, radical polymerizable inks are widely used from the viewpoints of production costs and storage stability of the inks.
It is known that radical polymerizable inks of the active-energy-ray-curable type contain acrylic acid esters that can suppress the viscosity of the inks and are curable with a small amount of light. It is also known that acrylamide compounds and N-vinyl compounds are used in combination with the acrylic acid esters in the radical polymerizable inks because these compounds can improve curability and close adhesiveness of cured films with bases and can raise the glass transition temperature.
In terms of, for example, curability, viscosity, and compatibility with other components, preferable examples of the acrylamide compounds and the N-vinyl compounds are compounds having a solubility parameter of around 11 (cal/cm3)1/2 and a low molar volume.
However, there is a problem that the active-energy-ray-curable inkjet inks decrease the elastic modulus of cured products of epoxy adhesives used for assembling ink discharging apparatuses, to degrade discharging stability of the inks.
Hence, there is proposed an ink discharging head in which an epoxy adhesive having a high solvent resistance and curable at a low temperature is used (see, e.g., Japanese Unexamined Patent Application Publication No. 2006-257350).
There is also proposed an ultraviolet-ray-curable inkjet ink composition excellent in ink discharging head durability and discharging reliability (see, e.g., Japanese Unexamined Patent Application Publication No. 2013-018853).